Dashpot



Patented Oct. 28,, 1924,

sTArEjs GAMALIEL c. s'r. Joan, or enzennwrcn, connncrrcur. i

DasHroT.

Application 'filed January 19, 1924. Serial No. 687,233.

7'0 (LZZ 10720771. it may conce/l'n: Be it known that I, GAMAL'LEL C. ST. JOHN, a citizen of the United States, and resident of Greenwich, in the county of Fairfield and State of Connecticut. have invented certain new and useful Improvements in Dashpots, of which the following is a specification. i

My invention relates to improvements in dash-pots and has for its object to provide a dash-pot in which substantially uniform resistance to the movement of the movable member or piston of the dash-pot will be encountered, whereby to resist vibration of a valve or other element connected with said member or piston of the dash-'pot and yet to permit such valve or element to have the required. extent of movement in due course.

I have illustrated my improvement in connection with a fluid meter valve and particularly in the class of steam meters set forth in Letters Patent No. 567,054, granted to me September 1, 1896, andv No. 599,746, granted tonie March 1, 1898.

My invention comprises novel details of improvement that will be more fully hereinafter set forth and then pointed out inythe olaims.

Reference is to be had to the accompanying drawmgs forming a part hereof, where1n- Fig. 1 is a Vertical section illustrating my improvement in connection with a steam n'ieter of the class before stated, and a o Fig. 2 is a detail section of a modification.

Similar numerals of reference indicate corresponding parts in the several views.

A dash-pot hollow shell or housing 1 is provided with an inner wall 2 shown projecting upwardly from the bottom 3 of said she'll and spaced from the inner surface of the latter, providing a chamberor space 4 therebetween. The wall 2 is in tubular form having a bore 5 opening through opposite ends of the wall to receive and guide a reciprocative rod 6. The 'movable member or piston 7 is shown in inverted cup-like form receiving the wall 2 to reciprocate along the same and extending over the open upper end of its bore 5, the member or piston 7 being located between wall 2 and theinner wallV of shell 1 within chamber 4 and spacedl therefrom for the accumulation of water or other fluid in said chamber. The upper closed end of the cup-like member or piston may be secured to rod 6 in any suitable way, as by threads 8 on said rod screwed into theend of the piston, a nut 9 on said rod securing the latter to the piston. The upper closed end of the pistonopposes the adjacent upper end of wall 2. The lower laterally extended portion 'Tafiof'memberof piston 7 is spaced with suitable clearance from the inner surface yof shelll within chamber 4 to serve in the nature of a piston to freely reciprocate and' to permit the flow of fluid between the edge of extension 7FL and the inner surface ofshell 1 in chamber 4. A lining 10, of brass or Vother suitable metal, may be provided in chamber 4. The diameter of the inner bore 7b ofpiston 7 is such Vthat the latter may reciprocate freely along a wall2 andV fluid may flow therebetween to a limited extent, and wherebywhen steam fiows along rod 6 within the bore 5 water of condensation may accumulate within chamber 4.

The shell 1 between its ends is provided with an inner transverse partition 11' having an axialbore or opening 12 in which the upper portion of member or piston 7 is adapted to receiprocate freely, there'being sufiicient 'clearance between the wall of bore 12 and member or Vpiston 7 to permit flow `Vof 'piston 7 rises its upper portion may enter chamber 4a/and water or other fluid that may be lifted by theextension 7a of the pisi ton may flow through the space between bore 12and the reduced upper portion of member oi'pist'on 7 from chamber 4 'into chamber 4, the partition`11 retarding the flowof the fluid. f a

In the form shown in Fig. 1 the wall 2 extends from the bottom 3 which is separate from the material of shell 1 and has a fiange 3a clamped securely in place between casing 13` and fiange 1a of Shell 1, the parts being secured together by means of screws 14. In a the form shown in Fig. 2 the shell 1, its bottom 3 'and the wall 2 are integral, the shell being secured upon'casing 13 by screws 14. A passage 15 communicates with chamber 4 and is shown provided with a pet cock 16 to permit drainage of the shell. A'sight CAS gage at 17 may be provided to indicate the height of water in the Clash-pot, which may be controlledt by apet cock 18. i

Although rod 6 may be actuated by any member whose movements are to be controlled I have illustrated said rod as connected with valve 19, which is the metering valve of a steam meter whose casing 13 is provided with a steam inlet at 20, al seat for valve 19 being` indicated at 21. A pressure equalizing shielfd is indicated at 22 and. an Outlet for ,the casing is indicated'at 23. rilhe casing 13 is shown vprovided with a hollow projection 2-1 in which a lever 25 is pivoted, the opening of which `projection may be closed byV a Vplugzf A recordifng or integrating machine A upon projection 2d may have a Stylus or other Viiidicating element' which maybe operated by- 'shaft 26 on lever 25 in any well knownV manne'r used in flvuidltmeters, which partsform n'opart of my lpre'sent invention but may be like those used iny my aforesaid Letters Patent, ory of any'l other desired construction rFhe valve 19 isV shown provided'vwith afgroove 27 'receiving a pi n.28 on lever 25, as usual.v The lower end of ro'd 6 is shown guided' at29.

nthe example illustrated the d-ash-pot is placed above the metering valve and above the main steam Chambery 18? of casing 13: so thatsubstances that may beV carried along with thesteam will notvaccrnnulate in the Clash-pot and may'fall below.v Steam that leaks past rod 6 through borel into the Clash-pot will ycondense in the l atte1',-and such water of, condensation wilflf charge the dash-pot, and iparticularly; the chamberl 11, thereo'` to asutiicient extent for controlling the operation of the ;Clash-pot member or piston 7 ',whreby as rodv 6: rises and descends with valve 19, (ajs,'lfor instance in the usual manner of steam meterst, of lthe class described), the member orpiston 7 Will control operation of said rod and valve, such. as vibrations thereof.V Sedimenh loose particles, grit, oxide, scalesandrust, oil, Vegetable eoncentratesand-- emulsions, etc., that may pass into the Veasingt 13 Z with; the steam through seat 21, past valve 19,1will be prevented from accumulating.. in thedash-pot by reasonof the elevation ofthe lattero above the current of steam i-ncasing;137 |hence the dash-pot is kep't free from interfering materialz and may perform itsoperation-without obstruction from extraneous substances, thereby .decreasingw frictioin avoiding breakage, providing `lrsteadiness .I of action,: ,facilitating the operationof the' meter, and revducing aimoyan'ce.A` Then the steam entering casing ltlfftises.. valve 19, rod 61 and member or piston of the .dash-pot the watei' ,upon the extension ,7a of said member or piston. will Ibe rais'eltand QrCd against the partition 11, to uiidue or 'too rapid rising of valve 19. Due to' tlieefiort of the valve to rise suchzwater will fiow downwardlyin the clearance space between extension 7 a and the inner surface of Chamber -1 until the position of the water is settled, above and below extension 7a, whereby the piston may come to restat the required position. Such resistance of the water against partition 11 has the effect to steady the action of the piston. Likewise, when the valve 19 seeks to descend the part 7zL of member or piston 7 will press upon the water beneath it in Chamber a and such water will gradually rise within, saidgohamber through the clearance space aforesaid, threby steadying, such action ofv the piston; 'n other words, the Upresence of the partition 11 in shell 1 spaced from lthe laottom rand in opposition to the extensionifflv of ,member or piston 7 servesnto retard quickaetion orjvibration of the latter, and ,Yet pe-rmits the required movement for positioning of valve 19 according to the workl required, it being understood, also, that when extension 7% of member or piston 7 rises-l water .may' fiow slowly into Chamber E21 and will defscvend fromthat Chamber into Chamber for eqfufalizlation with respect to member'or piston 7. In either movement of member or piston v7 the effect of Vacuum behind the extension 7% also Vserves to steady the action. of the piston and to ind'uce the flow ofwaterl behind the ,extension 7. i

I am aware that dash-'potshave been/providedI with springsor air resistance -Iag ainst the movement Of-their pistons but the increasing tension of the Springs andthe compression lof the aircreates an i-nereasingresistance against thestrokes of the'pistoin which resistance continues to oppose the piscton,when at rest, and S0 "011:, Wherea-s accordance. with I my i i 1,ve11-.tioi i;when` liquid is used the piston is not opposed by varying pressure inits ,movementsasince the liquid within chamber 4: of the dash-pot may flow and settle or equalize itsl position on opposite sid'es of the extension7a of, thet'member or :piston 7 the latter then :notfbeingpressed reversely against its initial movement, al.- though movement of thepiston in either direction initially resisted either by the liquiclA pressing against the partition `11` or against the lbottom 3 of. thedasli-pot when the piston movesxin conjfunctionfwith the vaeuumreferredto:1111 other words, my improvements permit smooth operation. ofzthe member or 'piston 7 in all-of its'positi-ons with-substantially equal resistance at all points of its movements.v w. i r

ILIavi'ngV now described my invention what I ol'aim is: V o A 1.;-A dash-potcomprising alshell having a plurality/ of; chambers a ,partition .provided withan opening: .between said chambersfand a movablelrmember Vin one; oflsaid, chamhers V.and operative to force fluid.. against said' Partition, said shell and member being spaced to Permit fluid to flow between said shell and member.

2. A Clash-pot comprising a hollow shell provided with an inner wall spaced from the shell, a Partition Within the shell between its ends providing chambers on opposite sides of the Partition, said Partition having an opening providing communication berality of communicating chambers, a wall within one of said ohambers spaced from the inner surface thereof and axially disposed respeeting the opening of the Partition, a movable member within one of said chambers operatively disposed respecting said wall and opening, a clearance space being provided between said member and said partition at said opening -and a olearanoe space being provided between said movable member and the inner surface of its Chamber to Perinit the flow of fluid through said clearance spaces, and means to aetuate said member.

5. A Clash-pot comprising a hollow shell provided With a transverse Partition having an opening dividing the Shell into a Plurality of communicating ohambers, a wall within z one of sald chambers spaced from the inner surface thereof and axially disposed respecting the opening of the Partition, a movable member reeeiving said wall and reeiprocative in the opening of said Partition, said movable member being sPaeed from the inner surface of one Vof said chambers and provided with an extension at its lower part opposing said Partition, the upper portion of said member being freely operative in the opening of said Partition and said extension being spaced from the inner surface of its Chamber to provide a clearance space therebetween, and means to aetuate said member.

6. A Clash-pot eomprising a hollow Shell provided with a transverse Partition having an opening dividing the Shell into a plurality of communicating chainbers, a wall within one of said ohambers spaeed from the inner surface thereof and axially disposed respecting the opening' of the Partition, a cup-like piston operative along said Wall and provided With a lower laterally disposed extension opposing said Partition, the upper portion of the piston being freely operative in the opening of the Partition and the extension of the piston being spaced from the inner surface of its Chamber to provide a elearance space for the flow of fluid betweensaid surface and said extension, and a rod operative in said Wall and connected with the Piston to actuate the same.

GAMALIEL o. ST. JOHN. 

